第1个回答 2017-02-22
The rearrangement of the blastula into a three-dimensional organism with inner, middle, and outer layers occurs during gastrulation. The resulting gastrula consists of an outer ectoderm, an inner endoderm, and a mesoderm layer positioned between them.
在原肠胚形成过程中,囊胚重新排列,形成包括内层,中层,外层的三围组织。最终原肠胚由一个外肠胚,内肠胚,和一个中肠胚构成。